whats the difference between the 96-98 4.6 motors and the 99-04 motors. what causes such a power increase?

 

96-98 has about 215 hp, 99-04 has about 260 hp. The difference comes with improved heads, more aggressive cam and tune on the 99-04 models.

 

The heads and intake were changed in 99 to the PI style (performance improved) I believe the cams might have been changed also but im not sure...

 

so how much will it take to get an early 4.6 to perform like the 99-04?

 

pi swap... theres a ton of information on it, just google pi swap and u should get alot of useful information

 

You can do a head swap to the 99-04 PI heads. You also have to change intake when doing this. Its a fairly common swap, there should be lots of info here on how to do it. With that swap, and a tune you should be making just a little more power than the 99-04's.

 

cause i was looking at this car and it says it has a pi conversion. what do you guys think is this a reasonable price?http://www.autotrader.com/fyc/vdp.js...000&cardist=12

 

I couldnt get that to work

 

Here's a WORKING LINK that doesn't make the thread go gay. For long links please use the link feature of the site... isn't that a rule or something?

It says it has the PI swap done, so you can expect it to have a bit more power than a 99-04 GT (the 96-98 GT's don't have dished pistons, 99-04 do, so you'll have a slightly higher compression ratio... only about a half a point. You should still use premium fuel though).